﻿// Upgrade NOTE: replaced '_Object2World' with 'unity_ObjectToWorld'

Shader "Custom/NormalMapWorldSpaceMat"
{
    Properties
    {
        _Color("Color Tint",Color) = (1,1,1,1)
        _MainTex("Main Tex",2D) = "white" {}
        _BumpMap("Bump Map",2D) = "bump" {}
        _BumpScale("Bump Scale",Float) = 1.0
        _Specular("Specular",Color) = (1,1,1,1)
        _Gloss("Gloss",Range(8.0,256)) = 20
    }
    SubShader
    {
        Pass
        {
            Tags {"LightMode"="ForwardBase"}
            
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "Lighting.cginc"
            
            fixed4 _Color;
            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _BumpMap;
            float4 _BumpMap_ST;
            float _BumpScale;
            float4 _Specular;
            float _Gloss;
            
            struct a2v
            {
                float4 vertex:POSITION;
                float3 normal:NORMAL;
                float4 tangent:TANGENT;
                float4 texcoord:TEXCOORD;
            };
            
            struct v2f
            {
                float4 pos:SV_POSITION;
                float4 uv:TEXCOORD0;
                float4 TtoW0:TEXCOORD1;
                float4 TtoW1:TEXCOORD2;
                float4 TtoW2:TEXCOORD3;
            };
            
            v2f vert(a2v v)
            {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);
                
                o.uv.xy = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
                o.uv.zw = v.texcoord.xy * _BumpMap_ST.xy + _BumpMap_ST.zw;
                
                float3 worldPos = mul(unity_ObjectToWorld,v.vertex).xyz;
                float3 worldNormal = UnityObjectToWorldNormal(v.normal);
                fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);
                float3 worldBinormal = cross(worldNormal,worldTangent) * v.tangent.w;
                
                o.TtoW0 = float4(worldTangent.x,worldBinormal.x,worldNormal.x,worldPos.x);
                o.TtoW1 = float4(worldTangent.y,worldBinormal.y,worldNormal.y,worldPos.y);
                o.TtoW2 = float4(worldTangent.z,worldBinormal.z,worldNormal.z,worldPos.z);
                
                return o;
            }
            
            fixed4 frag(v2f i):SV_Target
            {
                float3 worldPos = float3(i.TtoW0.w,i.TtoW1.w,i.TtoW2.w);
                fixed3 lightDir = normalize(UnityWorldSpaceLightDir(worldPos));
                fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos));
                
                fixed3 bump = UnpackNormal(tex2D(_BumpMap,i.uv.zw));
                bump.xy *= _BumpScale;
                bump.z = sqrt(1.0 - saturate(dot(bump.xy,bump.xy)));
                bump = normalize(half3(dot(i.TtoW0.xyz,bump),dot(i.TtoW1.xyz,bump),dot(i.TtoW2.xyz,bump)));
                
                return fixed4(bump,1.0);
            }
            ENDCG
            
        }
    }
    Fallback "Specular"
}